RESUMO: A associação de compostos naturais, isolados de plantas medicinais, com antibióticos convencionais, com mecanismos de ação semelhantes, torna-se uma estratégia alternativa e viável para superar o problema da resistência. Assim, nosso objetivo foi avaliar a atividade antimicrobiana in vitro de substâncias tânicas presentes na casca de Anacardium occidentale e Anadenanthera colubrina associadas à cefalexina, sobre amostras de Staphylococcus aureus. Avaliamos essa associação por meio da determinação da concentração mínima inibitória. Dessa forma, taninos e a cefalexina foram dissolvidos de forma seriada em água destilada em concentrações variando de 0,976 mg/mL a 500 mg/mL e 2 µg/mL a 512 µg/mL, respectivamente. Quando associados, inibiram o crescimento de S. aureus formando halos que variaram de 0,9 a 46 mm com concentração mínima inibitória de 7,8 mg/mL (taninos)/ 4 µg/mL (cefalexina). O efeito resultante da associação de substâncias, natural e sintética, com mecanismos de ação semelhantes, apresentou resultados superiores aos observados quando testados isoladamente. Podemos concluir que os taninos e a cefalexina tiveram sua ação antimicrobiana potencializada quando utilizados em associação, permitindo o uso de uma menor concentração, mantendo seu efeito antibacteriano sobre cepas de S. aureus.

ABSTRACT: The association of natural compounds isolated from medicinal plants with conventional antibiotics, both with similar mechanisms of action, have become a viable alternative strategy to overcome the problem of drug resistance. This study aimed to evaluate the in vitro antimicrobial activity of tannic substances present in the bark of Anacardium occidentale and Anadenanthera colubrina against samples of Staphylococcus aureus when in combination with cephalexin. These combinations were evaluated by determining the minimum inhibitory concentration (MIC). For this purpose, tannins and cephalexin were serially dissolved in distilled water at concentrations ranging from 0.976 mg/mL to 500 mg/mL and 2 mg/mL to 512 mg/mL, respectively. When combined, the compounds inhibited S. aureus growth forming halos ranging from 0.9 to 46 mm with an MIC of 7.8 mg/mL (tannins) and 4 µg/mL (cephalexin). The resulting effect of the combination of natural and synthetic substances with similar mechanisms of action presented better results than when tested alone. Thus, the conclusion is that both the tannins and cephalexin had their antimicrobial action enhanced when used in combination, enabling the use of lower concentrations while maintaining their antibacterial effect against strains of S. aureus.

As helmintoses gastrintestinais ocupam lugar de destaque na produção de pequenos ruminantes como um fator limitante e o seu controle vem sendo realizado por meio do uso indiscriminado de anti-helmínticos favorecendo o surgimento da resistência a medicamentos. Com o objetivo de comparar a ação anti-helmíntica das plantas Operculina hamiltonii (batata de purga), Marmodica charantia (Melão de São Caetano) e do moxedctin a 0,2% sobre as infecções helminticas naturais de caprinos, foram utilizados 40 caprinos, sem raça definida, fêmeas, com idade entre seis e 12 meses, naturalmente infectados, separados em quatro grupos: o GRUPO 1 (G1) - animais controle negativo tratados com água destilada; o GRUPO 2 (G2) - animais tratados com o extrato alcoólico da O. hamiltonii; o GRUPO 3 (G3) - animais tratados com o extrato alcoólico da M. charantia e no GRUPO 4 (G4) - animais controle positivo tratados com moxidectina 0,2%. Todos os grupos receberam os tratamentos por três dias consecutivos. As amostras fecais foram coletadas nos dias 0, 30 e 60 após tratamento, para a realização da contagem de ovos por grama de fezes (OPG) e larvacultura. Para avaliar o efeito dos tratamentos, aplicou-se o teste de redução na contagem de ovos por grama de fezes (RCOF). A RCOF do G2, G3 e G4 foram de 63 e 90; 40 e 40; 100 e 100%, respectivamente para 30 e 60 dias pós-tratamento respectivamente. Durante o período de estudo, observou-se que todas as amostras coletadas estavam positivas para larvas de helmintos da superfamília Trichostrongyloidea, com exceção para o G4, nos dias 30 e 60 pós-tratamento. O Haemonchus foi o parasita mais prevalente nas coproculturas.

Gastrintestinal helminthosis occupy a place of prominence in the production of small ruminants as an edge factor. Its control has been carried through the indiscriminate use of anti-helminthic products in favor of the appearing resistance to the medicines. With the objective to compare the anti-helminthic action of the Operculina hamiltonii plants (potato of purges), Marmodica charantia (Cantaloups of Sao Caetano) and of moxedctin at 0.2% about the natural helminthic infections of goats, there had been used 40 goats, without defined race, females, with age between six and 12 months, naturally infected, separated in four groups: GROUP 1 (G1) negative control animals treated with distilled water; GROUP 2 (G2) -animal treated with the alcoholic extract of O. hamiltonii; GROUP 3 (G3) - animal treated with the alcoholic extract of M. charantia and GROUP 4 (G4) - positive control animals treated with moxidectina at 0.2%. All of them had received the treatments for three days in a row. The feces samples were collected at: 0, 30 and 60 days after treatment, for the accomplishment of the egg counting per gram of excrements (EPG) and larvae culture. To evaluate the effect of the treatments, a reduction on the egg counting per gram of excrements (RECE) was applied. The RECE of the G2, G3 and G4 were: 63 and 90; 40 and 40; 100 and 100%, respectively for 30 and 60 days post-treatment, respectively. During the period of study it was observed that all collected samples were positive for larvae of helminths of the superfamily Trichostrongyloidea, except for the G4, throughout 30-60 days and post-treatment. The Haemonchus was the most prevalent parasite in the culture of feces.

Various species of mushrooms belonging to genus Pleurotus (Fr.) Kumm. are known by its nutritional value and medicinal properties, particularly anti-tumor activity and immunomodulation, related to structural polysaccharides. In order to study the composition and the effects of aqueoussoluble constituents from Pleurotus ostreato-roseus Sing. on mice serum proteins, the P. ostreato-roseus strain POR-020 was cultured on powered grass-sugarcane bagasse-sawdust-wheat bran-substrate, and fruiting bodies were produced, milled, extracted with ethanol and hot water, and fractional precipitated with ethanol producing two fractions, FI-1 and FI-2. These fractions showed, respectively, 47.87 and 26.45% (d. m.) carbohydrate, and 2.07 and 1.97% (d.m.) protein composition. The fractions were administered i.p. in AJ male mice in a singledose of 257 mg/kg (FI-1) and 31.5 mg/kg (FI-2). After 15 days administration, electrophoretic analysis of serum proteins detected that FI-1 increased 50, 25, 0.35, and 28.6% in b-, a1-, a2- and g-globulin regions, and FI-2 increased 4.4 and 21 % in band a1-globulin, respectively.